"Scout explains that her mother was taken from their family some years earlier, leaving their father Atticus to raise his children on his own," Ms Cusack said.

"When the children asked why God had taken their mother, Atticus explained, 'It must have been because he needed her up in heaven'.

"So Scout concludes that God must have really needed her up there, because she was so badly needed down here.

"I can only speculate, as Scout did, that God must have needed David very badly in heaven, because he was so loved and needed here with us."

After being diagnosed with terminal cancer, Mr Stevens went public with his story out of fear no one would be an advocate for the cannabis oil that so helped his daughter Deisha.

"David wanted me to visit him at home in Coffs Harbour to meet his family and view his extensive library of photographs and videos documenting the effects a rare genetic disease, Rubinstein-Taybi syndrome, has had upon his daughter Deisha," Ms Cusack said.

"The symptoms include severe epilepsy, which involved up to 2000 fits a day and long periods of almost catatonic state where in fact little Deisha was experiencing a barrage of fits damaging her brain and tiny body.

"David had rigged his own computer monitoring system, including cameras and alarms, in Deisha's bedroom.

"He showed me videos of life before they discovered cannabis oil, where every night he and Jamaica would respond to alarms that woke them several times, run full-tilt into her bedroom and in the worst case I saw little Deisha had stopped breathing and David administered resuscitation whilst Jamaica rushed to call an ambulance."

The administering of medicinal marijuana not only reduced Deisha's fits - it has stopped them altogether.

"He confided to me last year that the disappointing news that he had terminal cancer had prompted him to go public for Deisha," Ms Cusack said.

"He was terrified of not being there to advocate for her.

"He wanted reform faster and he wanted kids like Deisha up there at the top of the list."

Mr Stevens's dying wish appears to have been successful, with the NSW Government announcing in December it would begin clinical trials to examine how marijuana could provide relief to patients with a terminal disease.

"It may sound odd but I want to say this because David sounds like a saint, and he was," Ms Cusack said.

"He was also a really cool guy. He was a fit, knockabout North Coast bloke with fantastic mates and a permanent smile."